Head-motion for concentrating-tables



N. MOSSBERG.

HEAD MOTION FOR CONCENTRATING TABLES.

2 SHEETS-SHEET I.

Patented .Mar. 30, 1920.

APPLICATION FILED MAY 41,1918. 1,335,519.

- avwawt m jV/a Mash N. MOSSBERG.

HEAD MOTION FOR CONCENTRATING TABLES- APPLICATIQN FILED MAY41l9IB- 1,335,51 9. Patented Mar. 30, 1920.

2 SHEETS-SHEET 2 NELS MOSSBERG, 0F DENVER COLORADO.

HEAD-MOTION FOR CONGENTRAT ING -TABLES.

Specification of Letters Patent.

Patented Mar. 30, 1920.

Application filed May 4, 1918. Serial No. 32,518.

To all whom it may conccra'z:

Be it known that I, New T/IOSSBERG, a citizen of the United States,residing at the city and county of Denver and State of (olVorar/lo, haveinvented certain new and useful improvements in Heacl-lliotions fortoncentrating-Tables; and I do declare the :t'ollowing to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawings, and to thecharacters of reference marked thereon, which form a part of thisspecification.

luv invention relates to improvements in head motions, more especiallyadapted for use in connection with concentrating tables requiringa longstroke and, a differential movement, whereby the material thereon isgiven a tendency to travel in the direction of its reciprocation, thoughit must be understood that the mechanism is equally well adapted for usein other relations where a similar function is required.

As the more common use for this mechanism will be in connection withconcentrat-- ing tables, it will be described with special reference tothis use, though as above lndicated, it must be understood, that thecon-' struction is not limited to use with any particular construction.

As applied to a concentrating table, the device is connected with oneend of the table called the head, and the head motion is of suchcharacter that the material which is fed to one side of the table, isgiven a general tendency to travel toward the foot or tail of the tableor the end opposite the end where the head motion is connected. Duringthis operation of the table, the wash water which is also delivered atthe edge of the table where the material is fed; serves to effect theseparation'of the metallic values from the gangue, the gangue beingcarried transversely across the table and discharged at the edge thereofopposite that where the feed takes place, both as to material to betreated and wash water.

This head motion-is of such construction that it imparts a differentialreciprocating movement to the table, the length of the stroke dependingon the length of a crank formed in the operating shaft which isconnected by means of a pitlnan with a. lever or oscillatory arm whichis connected with a concentrating table by a rod, one end of which isadj ustable on the lever by means of a screw which is journaledin partsconnected with a lever and engages a nut in the adjacent end of theconnecting rod. By adj usting the lever end of the connecting rod, thelength of stroke may be regulated for a given crank throw.

The mechanism briefly described in the preceding paragraph will impartreciprocating differential movement to the concen trating table, butalone it is objectionable for the reason that there is undue wear on thejoints which soon results in lost motion, and consequently the requiredfunc tion is imperfectly performed. In orderto overcome this difficultyI arrange a second lever or oscillatory arm preferably rearward of thefirst named lever and between the latter and the crank shaft. The upperend of the second lever or that remote from its fulcrum is connectedwith the concentrating table independently of the first named connectingrod, while between the upper extremity of the second lever and itsfulcrum a yoke is connected with the second lever, the yoke having across head arranged in opposing relation to a stop mounted upon astationary rod, a spiral spring being arranged on the rod between thestop and the cross head This springserves to keep the table and all theparts of all the joints in close engagement during'the'movement of thetable or other body with which the head motion is connected. This springis placed under tension during the forward movement of the table and itsrecoil cooperates with the crank shaft in effecting the return movementand at the same time maintains the parts of the joints in closerelation, as above indicated.

Having briefly outlined my improved head motion I will proceed todescribe the same in detail, reference being made to the accompanyingdrawing in which is illustrated an embodiment thereof. In this drawing:

Figure 1 is a vertical longitudinal section taken through my improvedhead motion on the line 1-1, Fig. 2, showing the same connected with thebody to be reciprocated.

Fig. 2 is a top plan view of the same with the forward connectionspartly broken away. This is a view looking in the direction of arrows 2,Fig. 1, with the upper part of the housing removed.

Fig. 3 is asection taken on the line 33, Fig. 1 looking toward the left.

Fig. 4 is a view similar to Fig. 1 but showing the parts in differentrelative positions.

Fig. 5 is a section taken on the line 55, Fig. 4 looking downwardly.

Fig. 6 is a side elevation of the structure with the inclosing housingapplied.

The same reference characters indicate the same parts in all the views.Let the numeral 5 designate a stationary frame work which as illustratedin the drawing, is composed of two vertically disposed parallel sidemembers 6 and front and rear members designated 7 and 8 respectively. Tothis frame work which as shown is provided with openings 3 on oppositesides, a removable housing member 9 may be applied, the same having ahand piece 4 for convenience of manipulation.

A lever 10 occupying an upright position is fulcrumed on trunnions 12extending horizontally from a block 26 secured to the upper extremity ofthe lever, these trunnions being journaled in boxes 13 mounted on theframe on opposite sides of the lever, thus giving a strong and stablesupport for the lever and the parts connected therewith, as

hereinafter described. The lower extremityv of this lever or that remotefrom the fulcrum is provided with a part 14 which is pivotally connectedin the rear. as shown at 15, with the forward end of a pitman 16, therear extremity of the pitman being con.- nected with the crank 17 of acrank shaft 18-, the latter being journaled in boxes 19 mounted on therear part of the frame. This crank shaft is provided at one extremitywith fast and loose pulleys 20 and 21 respectively, the fast pulleypreferably serving as a fly wheel and constructed accordingly.

The part 14 which is secured to the lower extremity of the lever 10 orthat remote from the fulcrum trunnions 12, extends forwardly of thelever, as shown at 22, andin it is journal d as shown at 23. thelowerextremity of a screw 24 which is parallel with the lever 10, its upperextremity being journaled, as shown at 25, in the block 26 secured tothe upper extremity of the lever and fast thereon, as heretofore stated.

The upper extremity of this screw is provided with a hand wheel 27 forconvenience of manipulation. A member 28 is slidablv connected with. theshaft 10 between the block 26 and the member 14, while the screw 24 isthreaded in the member 28 forward of the lever. Hence, as the screw isturned, the member 28 is vertically adjusted on the lever intermediateits extremities. The forward end of the member 28 is pivotallyconnected, as shown at 29, with the rear extremity of a rod 30 whoseforward extremity is pivotally connected, as shown at 31 with the memberto be reciprocated, which may be designated by the numeral 32 whichindicates two beams which are stationary with the concentrating table orother member to be reciprocated.

As the crank shaft is rotated the body 32 will be given a differentialreciprocating movement which would have a tendency to cause the materialthereon to travel forwardly.

A second lever 33 is arranged in the rear of the first named lever andis provided at its lower end with a horizontally disposed hub 34 which,as shown in the drawing, is integral with the lever and rotatablyconnected with the frame by means of a spindle 35 which passes throughperforations in the frame and an alined perforation in the hub. Thislever 33 is provided a short distance above its fulcrum with a shorterspindle 36 -which passes through a reinforcement 37 in the lever, theopposite extremities of the spindle being respectively connected withthe forward ends of two spaced parallel rods 38, which rods pass throughthe protruding extremities of the spindle 36 and are connected with thelever by nuts 39. The rear ends of these rods are connected with a crosshead 40 which is slidable on a central rod 41 whose rear extremitypasses through a perforation 42 in the lower part of the frame, itsforward end being threaded into a stop nut 43. A spiral spring 44surrounds the rod 41 and is arranged between the cross head 40 and thestop nut 43. By rotating the rod by applying a wrench to its head 45,the tension of the spring may be regulated, since by such operation thenut will be made to travel either forwardly or rearwardly, as may berequired.

The upper extremity of the lever 33 which is bifurcated as shown at 46,is provided with a short shaft or spindle 47 which is journaled in theopposite parts of the bifurcated portion, and a rod 48 is passed througha perforation in the spindle and connected, as shown at 49, with thecenter of a plate 50, whose opposite extremities are connected, as shownat 51, with the arms 52 of a yoke 53 whose forward end is formed into aloop 54 which is connected with a hook 55 of a rod 56, the latter beingcon nected with the body 32 to be reciprocated, as shown at 57 and 58. I

From the foregoing description the use and operation of my improved headmotion will be readily understood. This structureas illustrated is welladapted for imparting a relatively long stroke to the body to bereciprocated, as distinguished from an exceedingly short stroke, whichis usual with differential head motions for concentrating tables, thoughit is evident that as short a stroke as desired may be obtained throughthe medium of my improvement. The stroke is regulated by the crank shaftand by the position of the adjustable member 28 upon the lever 10.

It is evident that as the crank shaft is rotated a differentialreciprocating movement will be imparted to the body 32 through themedium of the pitman 16, the lever 10 and the connecting rod 30. Duringthe forward movement or that toward the left, referring moreparticularly to Figs. 1, 2 and 3 of the drawing, the parts of thedifferent oints, as those at both extremities of the pitman, the jointbetween the connecting rod 30 and the member 28! andi, the joint betweenthe forward eXtremitiy of the rod 30 and the body to be reciprocated,are necessarily held in close contact on the forward side, since thepower comes from the crank shaft and is exerted in a forward direction.During the movement in the opposite direction, in the absence ofmechanism which utilizes the spiral spring .4., there would be atendency to produce wear in these joints and result in lost motion whichhas been found by experience to seriously interfere with. the properperformance of the function of a device of this character. By theemployment of the spring, the parts are held in close contact in bothdirections during both strokes, and the spring exerts a cushioningefiect at the ends of both strokes, thus obviating any undue wear duringthese periods of the operation of the device. This is a very importantpoint, and the spring and the mechanism connected therewith andconnected with the body to be reciprocated serve to produce this Iresult.

Attention is called to the fact that the location of the spring 44: welldown in the frame work and so that its axis intersects the lever 33close or comparatively close to the fulcrum, makes it practicable toimpart a relatively long stroke to the table while the movement of thespring is comparatively little. For instance, when the parts areconnected substantially, as shown in the drawing in Figs. 1 and 2, whilea four inch stroke may be imparted to the table, the movement of thespring is only about one inch. These proportions may be varied atpleasure by adjusting the member 28' upon the. lever 10, since thehigher this member, the shorter the stroke and consequently, the lowerthis member, the longer will be the stroke imparted to the table. Itshould be explained that there is a limit to the movement of a spiralspring in the direction of its axis and as compared with'its length, inorder that the life of the spring may be of such length as to make itsuse practicable. The mechanism cooperating with the spring in myimproved head motion is constructed and arranged with reference to themechanism directly connecteo and operated by the crank shaft to producethis result. By virtue of the sliding movement of the member 28 upon thelever 10, a relatively wide range of variation in stroke is available inmy improved head motion structure.

By reference to the drawing it will be understood that in Fig. l theparts are positioned to correspond with their location when in themiddle of the stroke, while in Fig. l the full line position of theparts corresponds approximately with their position at the end of theforward stroke, while the dotted lines indicate their positionapproximately at the end of the rearward stroke.

The parts 10 and 33 which have been referred to as levers in thedescription may perhaps more properly be termed oscillatory arms, andwill be so designated in the claims.

Attention is called to the fact that in my improved construction thedifferential character of the movement results from the fact that thepitman is connected with the oscillatory arm 10 beyond a horizontal linepassing through the axis of the crank shaft. In other words, if thepitman 16 were so connected with the oscillatory arm 10 that ahorizontal line cutting the axis of the crank shaft would pass throughthe axis of the crank and the point where the pitman is connected withthe arm 10, when the body 32 is at its forward limit of movement, therewould be no differential movement imparted to the body, since the axisof the crank would pass through the same length of arc in making boththe forward and rearward strokes, and consequently, the time occupiedduring both strokes of the table would be the same. Hence, there couldbe no differential movement such as is required in concentrating tablesfor instance, in order to cause the material to travel forwardly, I willsay, upon the table during the operation of separating the concentratesfrom the gangue on the principle heretofore outlined. In order to obtainthis differential movement I connect the pitman 16 with the oscillatoryarm 10 at a point below a horizontal line cutting the axis of the crankshaft, the result being that the axis of the crank travels through agreater length of arc while imparting the forward stroke to the body tobe actuated than while imparting the rearward stroke, and consequently,as the crank is traveling at the same speed while imparting bothstrokes, the rearward stroke must be accomplished in less time than theforward stroke and the table must travel. more rapidly during therearward stroke. This is the so-called differential characteristic of myimproved head motion.

Having thus described my invention, what I claim is:

1. In apparatus of the class described, the combination with a body tobe actuated, of an oscillatory arm connected with said body, a crankshaft, a pitman connecting the arm with the crank of the shaft to impartdifferential reciprocating movement to the body, a second oscillatoryarm, aconnection between said last named arm and said body independentof the connection between the first named arm and the body, and a springconnected with the second arm to have its tension alternately increasedand released as the body is actuated.

2. In apparatus of the class described, the

combination with a body to be actuated, of

an oscillatory arm connected with said body,

a crank shaft, a pitman connecting the arm with the crank of the shaftto impart differential reciprocating movement to the body,

a second oscillatory arm, a connection between said last named arm andsaid body independent of the connection between the first named arm andthe body, and a spring connected with thcsecond arm to have its tensionalternately increased and released as the body is actuated, the saidlast named connection being such as to impart to the springcomparatively little movement.

3. A differentialhead motion comprising in combination with a body to beactuated, two oscillatory arms independently connected with the saidbody, a crank shaft connected with one of said arms for impartingreciprocating movement to the said body, and a spring connected with theother arm to be alternately placed under tension and released.

4. A differential head motion comprising in combination with a body tobe reciprocated, an oscillatory arm, an operative connection betweensaid arm and said body, means for imparting oscillatory movement to thearm to reciprocate the body, and a spring held oscillatory armindependently connected with the body.

5. ii. differential head motion comprising in combination with a body,an oscillatory arm, an operative connection between said arm and saidbody, means for imparting oscillatory movementto the arm to reciprocatethe body, a second oscillatory arm connected with thebody independentlyof the first named arm, a stationary rod, a stop carried thereby, across head slidable on the rod, other rods connecting the cross headwith the second oscillatory arm, and a spiral spring mounted on thestationary rod between. the cross head and the said stop.

In testimony whereof I aflix my signature.

NELS MOSSBERG.

